Rhamnolipids: from biosynthesis to applications

Rhamnolipids are highly promising biosurfactants distinguished by remarkable surface and interfacial activities, inherently rapid biodegradability, and excellent bioactivities, endowing them with significant potential applications. This review provides a comprehensive overview of rhamnolipids from synthesis to applications. First, the microbial producers are outlined, along with rhamnolipid biosynthetic pathways in both Pseudomonas aeruginosa and Burkholderia species, with an emphasis on their differences governing rhamnolipid biosynthesis. Subsequently, metabolic engineering strategies for enhancing rhamnolipid production are systematically summarized, including strain optimization, promoter engineering, enhancing precursor supply, weakening metabolic competition, and protein engineering. Specially, tailor synthesis of rhamnolipids was reviewed, focusing on factors influencing their congener profiles and engineering approaches for customized production of specific homologue. Finally, the broad potential applications of rhamnolipids in the petroleum industry, agriculture, food, medicine, cosmetics, and soil remediation are explored. This paper is intended to serve as a reference for future research and practical applications of rhamnolipids.